1. Field of the Invention
The present invention relates to information processing. More specifically, the present invention relates to a method and device for a secured search.
2. Description of Related Art
Cloud computing is a service delivery model that provides convenient and on-demand network access to configurable shared computing resource pool. With the popularization of cloud computing, more people are encouraged to store and manage their information via the Internet. Users who manage their information through cloud computing are called as cloud consumers. For example, many cloud consumers taking advantage of cloud computing have emerged in the medical field, which includes websites such as PatientsLikeMe and Google health.
From the perspective of network resource utilization, websites such as PatientsLikeMe desires user (e.g. patient) information shared with other public individuals. However, people always want to preserve their privacy. According to a research in 2008, 25% of the participants chose to provide fake information when accessing a website, because 72% of the participants are concerned that their online information and behavior can be tracked and used by service providers, particularly in the medical field. The well-known medical website PatientsLikeMe encourages transparency of medical privacy to provide better healthcare service.
One approach to address this abovementioned problem uses information anonymization. In the information anonymization method, data are rewritten with generalization, suppression or perturbation, and other manners, in order to break the integrity of individuals' information while maintaining the features of the whole dataset. However, anonymized data generated in this method is preferred by research institutions rather than public individuals, because, after such perturbation, some types of information are unable to provide reasonable suggestions.
Another possible approach is a secured search. For example, users' sensitive data is encrypted. User sensitive data are generally invisible to searching users in search results, and a common searching user only can visit non-sensitive user data. Further, searchable encryption and index allow Information sharing. Thus, a searching user can access other users' whole data with those users' permission. However, this approach prevents effective information sharing, because permission from the users can render search results completely visible or invisible.
In view of the prior art, it is desired to provide a technique capable of realizing user information sharing to a greater extent while preserving user privacy.